This invention relates to photographic methods and apparatus and more particularly, it concerns a method and apparatus for automatically adjusting one or more functions of a photographic camera in accordance with indicia supplied with a container for film units adapted to be exposed in the camera.
It is well known in the photographic art to supply light-sensitive film in cartridges or cassettes capable of direct insertion into a camera and to provide the cartridge or cassette with some form of indicia corresponding to one or more characteristics of the film for cooperation with camera carried indicia responsive means to adjust various camera control functions automatically. U.S. Pat. Nos. 3,595,631 issued to Edwin H. Land, U.S. Pat. No. 3,672,752 issued to R. W. Young et al. and U.S. Pat. No. 3,848,985 issued to Stuart Bennett may be considered exemplary of a large number of prior art disclosures in this area. In the Land patent, for example, a cassette for a plurality of film units adapted for exposure and processing an instant camera is provided with a thermistor capable of effecting automatically exposure compensation for both film speed as well as temperature variation. The Young et al. patent features a coded film cassette in which the indicia is in the nature of a conductive strip or strips carried on the film cassette exterior to adapt both a camera and a projector for density variation of film carried in the cassette. The Bennett patent is typical of many systems in which the indicia is in the nature of an exterior surface formation on a film-carrying cassette and operative to regulate an automatic exposure control system when the cassette is inserted into the camera.
The general idea of providing a film-carrying cassette with some form of camera discernible indicia corresponding to one or more characteristics of the film contained in the cartridge or cassette has and continues to be used effectively for automatic control of camera exposure-parameter adjustment or other adjustments incident to the attainment of a high-quality photograph originating with the cassette-contained film unit or units. The increment of manufacturing expense attributed to the film unit container or cassette per se, however, coupled with the increment of manufacturing costs attributable to modifying the structure of such containers and correlating the insertion of film units into such cassettes leaves room for improvement from the standpoint of cost reduction. In addition, with the development of new films, increased ranges of variables are presented, thus requiring more versatile systems for representation of the cassette-contained film units than can be easily accommodated by variable physical characteristics of the cassette. Also, multiple variables in film, such as film speed, diverse sensitometry, color balance, and the like present a challenge to automatic adjustment of camera functions to accommodate each of such variables.